Generally, in an electronic device such as personal computers, copiers, and the like, many electronic components are arranged in a comparatively small housing. As a result, heat generated from electronic components accumulates in the housing, and this is likely to cause thermal destruction of the electronic components and serious trouble. Therefore at least a venting hole is formed on a wall surface and/or a ceiling surface of a housing of an electronic device, and the heat inside the housing is exhausted from the venting hole to the outside of the housing. Additionally, as a means for exhausting the heat to the outside of the housing actively and cooling the electronic device, it is generally known that an axial flow fan is arranged near the venting hole. It is required that noise of such an axial flow fan for cooling an electronic device is reduced as low as possible, and air flow performance is improved.
An axial flow fan comprises a casing having inlet and outlet, an impeller having a plurality of blades and a motor rotating the impeller. The motor is arranged on a base portion which is connected with a plurality of spokes consisting of linear shape which are integrally formed with the casing and having straight shape.
Additionally, it is known that a plurality of spokes are arranged on the outlet side of a casing, and a cross-sectional shape of the spokes is formed in an airfoil shape or a triangle shape, thereby the spokes work as stationary airfoils. In the event the spokes working as stationary airfoils are arranged on the outlet side of the casing, the spokes can increase the static pressure of air discharged from the outlet, and can rectify the discharged airflow. It is known that all these spokes are formed in a straight shape or in a curved shape. As an axial flow fan having spokes all of which are formed in a curved shape, in Japanese Patent No. 4808482 (hereinafter referred to as the conventional art), an axial flow fan having spokes all of which are formed in a shape convexly curved toward the rotational direction of the impeller is disclosed.
FIG. 6 is a front view of an axial flow fan disclosed in the conventional art. As shown in the FIG. 6, five static blades 102A to 102E are arranged in an outlet 101 of an axial flow blower 100. All of these stationary blades 102A to 102E have a shape convexly curved toward the rotational direction R of the impeller 110, and the stationary blade 102E has a groove portion 104 to accommodate a lead wire 103 for supplying electricity to the motor so as to pull out the lead wire 103 therefrom.
An outlet-side edge portion 105 of the stationary blade 102E is composed of two divided edges 105a and 105b respectively located at either side of a groove portion 104. Each shape of the two divided edges 105a and 105b in the vicinity of an internal end portion 106 is inclined so that a flat bottom surface 109 of a bottom wall portion 108 of a motor case and the two divided edges 105a and 105b are flush with each other.
The conventional art discloses that it becomes easy to insert the lead wire 103 into the groove portion 104 hereby.
However, according to the axial flow fan disclosed in the conventional art, although the two divided edges 105a and 105b, in the vicinity of the internal end portion 106, are inclined so that the flat bottom surface 109 of the bottom wall portion 108 and the two divided edges 105a and 105b are flush with each other and hereby it becomes easy to insert the lead wire 103 in the groove portion 104, it is necessary to arrange the lead wire 103 along the curved shape because the stationary blade 102E has a curved shape. Therefore, it is not necessarily easy to arrange the lead wire 103 into the stationary blade 102E and the workability is bad.